In a variety of bearing assemblies two bearings are disposed spaced in the axial direction. This can be necessary for different reasons. One application example is, for example, preassembled bearing units.
Here this can be, for example, a conventional bearing unit 1 shown in FIG. 3, for example, a truck hub bearing (truck hub unit or THU). The bearing unit 1 includes a common outer ring 2 that respectively includes on its radially inwardly facing side race surfaces 10 and 11 for a first rolling-element row 3 and a second rolling-element row 4, respectively. A separate inner ring 5 or 6 is respectively associated with the rolling-element rows 3 and 4. Here the outer ring is very long or has a large extension in the axial direction in order to realize an intermediate space in a region 7 between the race surfaces 10 and 11, which can also be referred to as raceways, and also to realize receptacles for seals 8 and 9 of the bearing unit 1. The outer ring 2 is usually manufactured from a rolling-element bearing steel.
Except for on the direct race surfaces 10 and 11, which can also be referred to as race zones, i.e., in regions wherein the rolling elements 3 and 4 roll on the outer ring 2, under certain circumstances no high-strength material is needed. Nonetheless in the manufacturing of the conventional bearing unit 1 a not-insignificant material section, namely in the regions indicated by the reference numbers 7, 8, and 9, must be processed, hardened, and transported. A complexity in the manufacturing of the product and thus also a cost component can thereby increase. This is undesired and can also occur in a variety of other bearing assemblies.
There is therefore a need to simplify the manufacturing of a bearing unit.